.TH std::iswblank 3 "2024.06.10" "http://cppreference.com" "C++ Standard Libary"
.SH NAME
std::iswblank \- std::iswblank

.SH Synopsis
   Defined in header <cwctype>
   int iswblank( std::wint_t ch );  \fI(since C++11)\fP

   Checks if the given wide character is classified as blank character (that is, a
   whitespace character used to separate words in a sentence) by the current C locale.
   In the default C locale, only space (0x20) and horizontal tab (0x09) are blank
   characters.

   If the value of ch is neither representable as a wchar_t nor equal to the value of
   the macro WEOF, the behavior is undefined.

.SH Parameters

   ch - wide character

.SH Return value

   Non-zero value if the wide character is a blank character, zero otherwise.

.SH Notes

   ISO 30112 defines POSIX blank characters as Unicode characters U+0009, U+0020,
   U+1680, U+180E, U+2000..U+2006, U+2008, U+200A, U+205F, and U+3000.

.SH Example


// Run this code

 #include <clocale>
 #include <cwctype>
 #include <iostream>

 int main()
 {
     wchar_t c = L'\\u3000'; // Ideographic space ('　')

     std::cout << std::hex << std::showbase << std::boolalpha;
     std::cout << "in the default locale, iswblank(" << (std::wint_t)c << ") = "
               << (bool)std::iswblank(c) << '\\n';
     std::setlocale(LC_ALL, "en_US.utf8");
     std::cout << "in Unicode locale, iswblank(" << (std::wint_t)c << ") = "
               << (bool)std::iswblank(c) << '\\n';
 }

.SH Output:

 in the default locale, iswblank(0x3000) = false
 in Unicode locale, iswblank(0x3000) = true

.SH See also

   isblank(std::locale) checks if a character is classified as a blank character by a
   \fI(C++11)\fP              locale
                        \fI(function template)\fP
   isblank              checks if a character is a blank character
   \fI(C++11)\fP              \fI(function)\fP
   C documentation for
   iswblank

        ASCII values            characters    iscntrl  isprint  isspace  isblank  isgraph  ispunct  isalnum  isalpha  isupper  islower  isdigit  isxdigit
decimal hexadecimal   octal                   iswcntrl iswprint iswspace iswblank iswgraph iswpunct iswalnum iswalpha iswupper iswlower iswdigit iswxdigit
0–8     \\x0–\\x8     \\0–\\10    control codes   ≠0       0        0        0        0        0        0        0        0        0        0        0
                              (NUL, etc.)
9       \\x9         \\11       tab (\\t)        ≠0       0        ≠0       ≠0       0        0        0        0        0        0        0        0
                              whitespaces
10–13   \\xA–\\xD     \\12–\\15   (\\n, \\v, \\f,    ≠0       0        ≠0       0        0        0        0        0        0        0        0        0
                              \\r)
14–31   \\xE–\\x1F    \\16–\\37   control codes   ≠0       0        0        0        0        0        0        0        0        0        0        0
32      \\x20        \\40       space           0        ≠0       ≠0       ≠0       0        0        0        0        0        0        0        0
33–47   \\x21–\\x2F   \\41–\\57   !"#$%&'()*+,-./ 0        ≠0       0        0        ≠0       ≠0       0        0        0        0        0        0
48–57   \\x30–\\x39   \\60–\\71   0123456789      0        ≠0       0        0        ≠0       0        ≠0       0        0        0        ≠0       ≠0
58–64   \\x3A–\\x40   \\72–\\100  :;<=>?@         0        ≠0       0        0        ≠0       ≠0       0        0        0        0        0        0
65–70   \\x41–\\x46   \\101–\\106 ABCDEF          0        ≠0       0        0        ≠0       0        ≠0       ≠0       ≠0       0        0        ≠0
71–90   \\x47–\\x5A   \\107–\\132 GHIJKLMNOP      0        ≠0       0        0        ≠0       0        ≠0       ≠0       ≠0       0        0        0
                              QRSTUVWXYZ
91–96   \\x5B–\\x60   \\133–\\140 [\\]^_`          0        ≠0       0        0        ≠0       ≠0       0        0        0        0        0        0
97–102  \\x61–\\x66   \\141–\\146 abcdef          0        ≠0       0        0        ≠0       0        ≠0       ≠0       0        ≠0       0        ≠0
103–122 \\x67–\\x7A   \\147–\\172 ghijklmnop      0        ≠0       0        0        ≠0       0        ≠0       ≠0       0        ≠0       0        0
                              qrstuvwxyz
123–126 \\x7B–\\x7E   \\172–\\176 {|}~            0        ≠0       0        0        ≠0       ≠0       0        0        0        0        0        0
127     \\x7F        \\177      backspace       ≠0       0        0        0        0        0        0        0        0        0        0        0
                              character (DEL)
